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Publication numberUS4488745 A
Publication typeGrant
Application numberUS 06/481,620
Publication dateDec 18, 1984
Filing dateApr 4, 1983
Priority dateApr 4, 1983
Fee statusLapsed
Publication number06481620, 481620, US 4488745 A, US 4488745A, US-A-4488745, US4488745 A, US4488745A
InventorsVijay K. Stokes
Original AssigneeGeneral Electric Company
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Supports for plastic motor vehicle bumpers
US 4488745 A
Abstract
A plastic support for attaching a plastic bumper to the metal frame of a motor vehicle comprises a metal pad having means for attaching the pad to the metal vehicle frame. The means for attaching the pad extends from, and is affixed to, one face of the pad. The pad is completely embedded in a moldable thermoplastic matrix except where the means for attaching the pad to the metal vehicle frame extends through the matrix. The matrix adjacent the other, or opposite, face of the pad is affixed to the plastic bumper, forming a plastic-to-plastic joint.
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Claims(7)
What is claimed is:
1. A plastic vehicle bumper support attaching a plastic bumper to a metal frame of a vehicle, comprising:
a pad of metal including means for attaching said pad to said metal vehicle frame extending from and affixed to one face of said pad; and
a moldable thermoplastic matrix embedding said pad, except where said means for attaching said pad to said metal vehicle frame extends therethrough, the plastic matrix adjacent the other face of said pad being fixed to said plastic bumper and forming a plastic-to-plastic joint with said plastic bumper.
2. The bumper support of claim 1 wherein said pad further comprises dovetail projections extending therefrom to anchor said plastic matrix.
3. The bumper support of claim 1 wherein said pad defines apertures extending between the pad faces to assure good adhesion of said plastic matrix.
4. The bumper support of claim 1 wherein said plastic-to-plastic joint is formed by vibration welding and said plastic matrix adjacent said other face of said pad including a plurality of ribs to assure good contact during vibration welding.
5. The bumper support of claim 1 wherein said means for attaching said pad to said metal vehicle frame comprises a tongue defining an aperture extending perpendicularly from said one face of said pad.
6. The bumper support of claim 1 wherein said means for attaching said pad to said metal frame comprises a tongue defining a pair of spaced-apart apertures extending perpendicularly from said one face of said pad.
7. A plastic vehicle bumper support for attaching to a plastic bumper and to a metal frame of a vehicle, comprising:
a pad of metal including means for attaching said pad to said metal vehicle frame extending from and affixed to one face of said pad; and
a moldable thermoplastic matrix embedding said pad, except where said means for attaching said pad to said metal vehicle frame extends therethrough, the plastic matrix adjacent the other face of said pad adapted to form a plastic-to-plastic joint with said plastic bumper.
Description
BACKGROUND OF THE INVENTION

This invention relates to plastic vehicle bumpers and more particularly to supports for attaching plastic bumpers to the steel struts of a motor vehicle frame.

Currently attachment of plastic bumpers to the body of a motor vehicle, such as an automobile with or without the use of shock absorbers, typically requires use of bolts for attaching the plastic bumper back face to the steel face of the strut extending from the automobile body. This has several disadvantages. First, holes are introduced in a region of high stresses resulting in unnecessary stress concentration in the plastic material. Second, slight variations on the amount of torque applied while tightening the bolt could result in excessive loads on the plastic which, in addition to giving rise to high stresses, could also introduce cracks. Third, such joints cannot be sealed properly and the resulting crevices could act as traps for solvents and other environmental agents that attack the plastic material, resulting in failure due to material degradation. Finally, the current approaches for attachment are cumbersome from the point of view of assembly, probably being based on how metal bumpers are assembled and attached to the supports.

It is an object of the present invention to provide an attachment support for attaching a plastic bumper to the metal frame of a motor vehicle, while avoiding any need for making holes in the plastic bumper.

It is a further object of the present invention to provide a sealed interface between the metal and plastic parts of a plastic bumper at the bumper support to avoid material degradation due to trapped solvents or environmental agents.

SUMMARY OF THE INVENTION

In one aspect of the present invention a plastic support for attaching a plastic bumper to the metal frame of a motor vehicle comprises a metal pad having means for attaching the pad to the metal vehicle frame. The means for attaching the pad extends from, and is affixed to, one face of the pad. The pad is completely embedded in a moldable thermoplastic matrix except where the means for attaching the pad to the metal vehicle frame extends through the matrix. The matrix adjacent the other, or opposite, face of the pad, is affixed to the plastic bumper, forming a plastic-to-plastic joint.

BRIEF DESCRIPTION OF THE DRAWING

While the specification concludes with claims particularly pointing out and distinctly claiming the present invention, the objects and advantages of the invention can be more readily ascertained from the following description of preferred embodiments when used in conjunction with the accompanying drawing in which:

FIGS. 1a, 1b and 1c are a top, rear and section views, respectively, of a bumper support affixed to a plastic bumper (of which only part is shown) in accordance with the present invention.

FIGS. 2a and 2b are perspective views of the front and rear faces, respectively, of the metal pad used in the support shown in FIG. 1;

FIGS. 3a and 3b are a side view and rear view, respectively, of another embodiment of a bumper support in accordance with the present invention; and

FIG. 4 is a perspective view of one side of an alternative configuration of a metal pad for use in the bumper support of the present invention.

DETAILED DESCRIPTION OF THE DRAWING

Referring to the drawing and especially FIGS. 1a-1c thereof, a support 7 for a plastic bumper is shown. The bumper support comprises a steel pad 9 embedded in a thermoplastic matrix 11. Extending from the rear face of the pad through the plastic matrix is a tongue or eye 13 having a hole 14. The bumper support 7 is attached to the plastic bumper 15, shown as a box beam bumper. The support 7 can be used with any type of plastic bumper including the double beam bumper shown in my copending application filed on even date herewith, entitled "Double Beam Motor Vehicle Bumpers", Serial No. (RD-14302) and assigned to the same assignee as the subject application. My copending application is hereby incorporated by reference. The bumper support is shown attached to bumper 15 by vibration welding, induction heating (using a conductive insert) or adhesive bonding could also be used. A clevis 17 with a hole 18, shown spaced apart from the eye 13, is part of the vehicle frame (not shown). The clevis, when attached to the bumper support, surrounds the eye 13 and a bolt (not shown) passing through holes 14 and 18 joins the clevis to the eye. Support 7 is a simple support (as opposed to a fixed support) since rotation of the joint in a horizontal plane is permitted.

Referring now to FIGS. 2a and 2b the structure of the pad 9 is shown. The pad 9 has a plurality of holes 21 spaced about, and extending from, one face through to the other, permitting the plastic matrix 11 to extend through the pad and reduce any tendency for the plastic matrix to pull away from the pad faces. Dovetail projections 23, most easily seen in FIG. 2b, are spaced about on the front face of pad 9. The dovetail projections 23 also help anchor the plastic matrix to the pad.

Referring to FIG. 2a, the eye or tongue 13 extends perpendicularly from the rear face of pad 9. The tongue typically of steel, can be welded to the rear pad and steel gussets 25 attached to the pad and the eye by welding to reinforce the eye. Steel tongue 13 is partially embedded and gussets 25 are fully embedded in the thermoplastic matrix of pad 9.

FIGS. 3a and 3b shows another embodiment of a support 7. The plastic matrix 11 includes, on the surface to be affixed to the plastic bumper, a number of raised horizontal ribs 24 running the entire width of the support. The ribs assure good contact during vibration welding of the plastic materials by reducing the effective area of the support contact face. The ribs could alternatively be positioned vertically. Dovetail projections 23 are provided to anchor the matrix to the pad.

FIG. 4 shows a metal pad 19 having a tongue or eye 26 with two spaced-apart holes 27. The corresponding clevis 17 for mounting the support to the metal frame is shown spaced apart from the pad. The pad 19, when used in the support 7 of FIGS. 1, 2 or 3, would provide a rigid fixed support, since the connection of this pad to the vehicle frame does not permit rotation.

The pad of FIGS. 1-4 is embedded in the plastic matrix 11 in a controlled environment so that the metal-plastic interface is sealed to keep out solvents and other corroding agents. The plastic matix could be injection molded, for example, in a cavity containing the pad. Suitable moldable thermoplastics which could be used are polybutylene terephthalate (pbt), polycarbonate resin, and a blend of polyphenylene oxide mixed with rubber-modified polystyrene. The above are available from the General Electric Company, for example, as Valox®, Lexan® and Noryl®, respectively. Alloyed compositions of the above such as pbt and polycarbonate available from General Electric Company as Xenoy™ could also be used.

The foregoing describes a plastic vehicle bumper support that does not require holes to be introduced into the plastic bumper and provides a sealed metal to plastic interface to avoid material degradation due to solvents and other environmental agents that attack plastics that might otherwise become trapped at the interface.

While the invention has been particularly shown and described with reference to several preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3850466 *Aug 14, 1972Nov 26, 1974Yepis AVehicle bumper and frame mounting
US3905630 *Feb 11, 1974Sep 16, 1975Houdaille Industries IncLightweight, low cost impact resistant bumpers
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4586738 *Jan 14, 1985May 6, 1986General Motors CorporationMolded plastic bumper and mounting bracket assembly
US5092643 *Oct 29, 1990Mar 3, 1992Toyoda Gosei Co, Ltd.Automobile bumper
US5117549 *Apr 9, 1991Jun 2, 1992Davidson Textron Inc.Automotive door panels and method of assembly therefor
US6318775 *Jun 21, 1999Nov 20, 2001Shape CorporationComposite bumper construction
US6871890 *Apr 11, 2003Mar 29, 2005Nissan Motor Co., Ltd.Bumper mounting structure for vehicle
US6879250 *Apr 4, 2002Apr 12, 2005Compagnie Plastic OmniumFor a motor vehicle, an outside element providing a capacitive sensor, and a piece of bodywork including such an outside element
US6918621Nov 12, 2003Jul 19, 2005Alcoa Inc.Bumper system for a motor vehicle
US7325642 *Jan 29, 2004Feb 5, 2008Compagnie Plastic OmniumMotor vehicle fender having a breakable zone
US8616596 *Feb 15, 2012Dec 31, 2013GM Global Technology Operations LLCFastening structure for a bumper of a motor vehicle
US20120217763 *Feb 15, 2012Aug 30, 2012GM Global Technology Operations LLCFastening structure for a bumper of a motor vehicle
EP1063135A2 *Jun 21, 2000Dec 27, 2000Shape CorporationComposite bumper construction
Classifications
U.S. Classification293/155, 403/267, 293/122, 403/220, 29/458
International ClassificationB60R19/24, B60R19/18
Cooperative ClassificationB60R2019/1833, B60R19/24, B60R19/18
European ClassificationB60R19/18
Legal Events
DateCodeEventDescription
Mar 2, 1993FPExpired due to failure to pay maintenance fee
Effective date: 19921220
Dec 20, 1992LAPSLapse for failure to pay maintenance fees
Jul 23, 1992REMIMaintenance fee reminder mailed
Mar 29, 1988FPAYFee payment
Year of fee payment: 4
Apr 4, 1983ASAssignment
Owner name: GENERAL ELECTRIC COMPANY, A CORP. OF N.Y.
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:STOKES, VIJAY K.;REEL/FRAME:004114/0203
Effective date: 19830331